Apparatus for extracting oils and the like.



E. O. BARSTOW & T. GRISWOLD, JR.

APPARATUS FOR EXTRACTING OILS AND THE LIKE.

APPLICATION FILED DEC-24,1914. 1,199,861; Patented Oct. 3,1916.

3 SHEETSSHEET 1.

E. O. BARSTOW & T. GRISWOLD, JR.

APPARATUS FOR EXTRACTING OLS AND THE LIKE.

APPLICATION FILED DEC-24, I914- Patented Oct. 3,1916.

A Mr/wassas: I 1 Y A jw z/vnoles' W' [FM 0. 0mm W @q 7 4 I y z I ZT B/w: 76 I E O. BARSTOW & T.-GRISW0LD, JR. I

APPARATUS FOR EXTRACTING OILS AND THE LIKE;

APPLICATION FILED DEC. 24, 191 4.

M 0W a ,m m 3 W 6 4 WW W EDWIN 0. BARSTOW ANIP THOMAS'GRISWOLD JR OF MIDLAND, MICHIGAN.

APPARATUS ronnx'rnac'r'mo oILs AND m1: LIKE. 7

Specification of Letters Patent.

' Patented Oct. 3, 1916.

Original application filedOctobei 9, ieiafsfiai No. 724,785.; Divided and this application filed Decembeg 24,1914. sci-m1 No. 878,840.

' ment in Apparatus for Extracting Oils and the like, of-which the following is a specification, the principle of the invention being herein explained and the best mode in which we. have contemplated applying that pr n ciple, so as to distinguish it from other 1n= ventions.

- 1915) out of which the The present improved apparatus relatesin general to the art of separating the more readily soluble constituents of materials from their less re dily soluble, or insoluble constituents by t e process of washing; More particularly, although in no sense exclusively, such apparatus, and the process exemplified in its operation, relate to the ex- 4 traction of oilsand the like from the materialin which theyare found, by treating such material with a suitable'solvent in such fashion as to take up therefromtheoil o'r the like, the latter being then subsequently separated from the solvent which may be utilized over and over again, and the object economic extraction of such materials. The process, or method, aspect of the invention it should be stated forms the subject of theinvention being to provide for thematter of a separate application filed Oct. 9,-

1912, Serial No. 724,785, (since issued mto Patent No." 1,125,920, dated January-.19,

been required to be divided.

The advantages over other apparatus now known to the inventors as being in use, are

many. The Working capacity or output is relatively very large compared to the -investment. The process is continuous and largely automatic, thus reducing'laborfzmd cost of attendance to a minimum.

tracted matter), high in'extracted matter is obtained andthe amount of'solvent left ad hering to the material after extra'ctionis relatively small, resulting in a relatively low present case has -1: 1 tion, or extract (mixture of solvent and'exfuel cost for solvent recovery. A relatively very small quantity .of solvent in process is required, thus reducing investment therein. The solvent in process is maintained in constant flow either as llqllldor vapor,

' and owing to the manner of its use and ,re-

. k a: I

covery, the actual quantity present inthe ,various portions of the apparatus with the exception of the solvent storage tank, is substantially constant, hence any loss of solvent will be at-once manifest by change in its surface level-or depth in said tank, a most im- 2 .portant" feature, enabling the operator to know" at all times, and for any lapse of time, the solvent consumption and the effik ciency of recovery, and a sudden change in ,such level or depth gives prompt warning of accidental loss by leakage .or otherwise before such loss shall have. grown to a ma- .terial amount. The application off heat in the solvent recovery steps is direct, effective and eflicient, insuring a substantially, complete and economical recovery, an important point in practical working. The

process is especially well adapted for the i use of carbon 'tetrachlorid as solvent, on

account of the small quantity required, the high efficiency of recovery and the promptness with which any loss is made evident, which features are particularly ,important because of the higher relative cpst gallon of this solvent.

To the accomplishment of the foregoing and related ends, the invention, then,-consists of-the means for carrying on the same,

' hereinafter fully described and particularly pointed out' in the claims.

. The annexed drawings and the following 'dGSCI'IlPtiOII set forth in detail certain mech anism for carrying out the 'invention su'ch' disclosed means illustrating, however, but several of thevarious ways in which the principle of the invention may be used.

vIn said annexed drawings i-Figure- 1 shows, in more or less diagrammatic formone' arrangement of our improved ".extr'ao tion apparatus; Fig.' 2 isa diagrammatic representation of the flow of the diflerent materials involved 1n the operation of such improved'apparatus;- Fig. 3 is a' plan view showing a modified. formof extractor from thatincluded inthe apparatus of Fig. 1; Fig; 4 is a transverse section of such modifiedapparatus on line 44;; and Fig, 5' is a broken longitudinal vertical section of the same taken on the line 5-5, Fig. 3.

The general arrangement of apparatus. illustrated in Fig. 1 is suitable for the treatment' of any material which can be delivered to it in the form of meal, either fine or coarse, and is furthermore adapted to the use of a volatile solvent heavier than water, such as carbon-tetrachlorid, tri-chlorethylene or the like; and, with slight modifications, for a solvent lighter than water, such as naphtha. The central piece of 'apparatus around which the .others are grouped is the extractor proper, a modified construction of which is illustrated ,in Figs.

3 4 and 5. Whatever its form of construction, such extractor is designed to operate on the order of a continuous filter whereon the material to be treated is caused to pass n a layer of greater or less thickness, while it is periodically treated with, and sepa-- rated from, the solvent; in other words,

the material and solvent may be regarded as movmg 1n currents whose gleneral directions of flow are opposite, but which currents are' cham'ber is controlled, the construction and operation of such regulator being reserved for I future descr1pt1on.

such as to cause the drum 1 to be partially The level of the mixture within the chamber however, isv

submerged therein, as clearly shown in "Fig. 1. o

The respective discharge lines 23, 24 and 25 from the pumps 15, 16 and 17 lead to separators 26, 27and 28, whiclrare adapted to receive the mixed air and solvent (such air and solvent being drawn through the pumps, as will be presently described), and

separate the same by gravity, the solvent :passing'ofi' by way of separate pipes 29, 30

and 31 and th'e'air by Way ofa common branched pipe 32. The air insuch pipe 32 will be underpressure, due to the hydrostatic'he ad measured from 'the level-of the li uid in the several separators (such level being indicated by dotted lines) to the outlet level ofsaid reservoirs which is the 'same in each being indicated by numeral 2, suitable means (not shown) being pro-- vided forthe purpose of rotating the same.

The cylindrical periphery of; the drum'is corrugated and covered wit a -pervious filter 3 of suitable .material, that forms acontinuous band around the drum over the corrugations. further divided ofl into a plurality of similar transverse sections 4, sixteen. being shown for--the purpose of illustration.

The surface of the drum is Each ofithese sections is provided with a port 5, such ports 5 opening in the surface is slidably held a stationary take-ofi valve 7 provided in the present instance with four ports 8, 9, l0j and 11, the first three of which are respectively connected by means of pipes 12, 13 and 14 with pumps 17,16 and 15. These pumps areadapted of a commutating valve 6 against which to create a suction through'the COIIGSPOIld-f ing pi es and ports and thus through the severa sectionslof the filter cover that happen to be in communicationjwith the re-- spective ports.

The filter at... 1 is inclosed within a tight casingor chamber l8, the lower portion ofwhich constitutes a receptacle for the reception of a mixture of the material to be treated and the solvent used in the extraction process, The material to' be" tractorf chamber.

33 in each case. .Suchhydrostatic head is controlled at will by means of an adjustable relief valve 34 connected to pipe 32' and venting into the housing 18. Located above and-parallel with the axis of the extractor drum within the casing 18 'that houses the same, aretwo troughs, or feed boxes 35 and36, ,the first of which is supplied with fresh solvent by way of pipe 37 from a storage. tank38; the second of which is suppliedb the pipe 29 leading from the overflow o separator 26.

The overflow of separator 27 is carried to a liquid inlet pipe 39 at the base of the chamber 18 by way of'pipes 30 and 40, a

h drostatic 'device,which controls the suppy of fresh solvent through pipe 37, being interposed between said two; pipes 30 and 40. This h drostatic device comprises a portion to form a chamber, the latter overflowing into the pipe 40, that leads to the liquid inlet pipe 39 at the bottom of the exdevice' is located a float 42 connected by means of arod 43 to the lever 44 of a valve 45 in the feed-pipe 37 for the fresh solvent.

in the chamber, will obviously rise and tall as 'the latter-varies in density. Assuming I the hydrostatic device. to be arranged for treated is fed into the chamber near. its bottom-by way of a spout 1,9 and ahopper 20, the. latter being attachedto the side wall of the chamber, with which it communicates through an openin 2.1 that preferably lies below the level of t e liqu1d'mixturew1th1n the chamber. Suchlevel is determinedby means of an automatic regulator 22, "by

which the supply of the solvent to a the v dealing with carbontetrachlorid, in extracting an oil lighter than such tetrachlorid should the extract become poorer in oil and hence heavier, the float will' rise, thereby actuating the valve 45 to decrease the flow of fresh solvent into the extractor; should, on the contrary, the extract become richer and actuate the valve to increase the flow of fresh solvent to the extractor. The connection Joetw'een the rod 43 and the lever 44 vertical stan pipe 41 enlarged at its upper In the chamber of the a j .This float, being immersed in the extract in oil and hence lighter, the float will sink form and constant level in same.

is adjustableso that the float can'be set to respond to any desired density or strength of extract in chamber 41, and when so .Set it, will automatically regulate the flow of fresh solvent to the. extractor, such regulation being based on the strength of the extract obtained. 1 I

The separator 28 into which pump 17 discharges, is designed normally to overflow into a stationary filter46, but the overflow from said separator is also connected by means of the pipe 31 with the regulator 22, previously referred'to, and thence with the extractor chamber by way of inlet pipe 39. The action of this regulator is normally to "close the connection of thei. pipe 31 therewith, so long as the mixture in said chamberis maintained at'a predetermined level. Should, however, this level fall, a float 47 in the regulator will drop correspondingly and thereby open a valve 48 and permit a portion, or all, of the extract over-flowing from the separator 28 to be diverted from filter 4.6-through pipe 31 to the extractor chamber 18.- Such lowering of the level obviously will occur only when the supply of extract over-flowing from separator 27 and passing thence through pipe 30, hydrostatic device 41, and pipe to the extractor chamber, is insufiicient .to maintain the predetermined level in saidicha-mber,

The normal course of, flow of the solvent may be, for the purposes of the description,

taken to be from the last extraction to the filter 46 although in actual operation the volume of this flow is less than that returnedto the extractor, in order to'maintain a uni- Under ordinary operating, conditions the valve .48 is alwaysopen and a continuous flow ofextractv is coming in through it and also a. continuous fiowis passing forward to the filter 46,

the. valve serving merely to automatically divide the total flow into two portions, one to the filter, the other to the extractor. The extract as it enters the chamber, Whether su plied through pipe 40-or pipe 31, is mixe with the untreated material as the latter is drawn away fromhopper 20 into the base of the extractor by the action of paddles '49 suitably rotated, as: need not be explained. The

opening from the hopper 20 into the extractor chamber, being below the liquor level therein, suchliquor traps the opening and preventsescape ofair and solvent vapor from the chamber 18, and the downwardly moving mass of material within the hopper forms .a stopper which further retards or prevents the vaporization ofjthe solvent which wets the'material in the base of the hopper.

Before proceeding with the description of the other associated parts of the general apparatus, the operation of the extractor proper may be advantageously reviewed. It

will be noted, then, that the materiaL as it is fed through the hopper into the extractor chamber 18 by 'the action of the paddles 49, is mixed with the extractflowing in through the pipe 39 such extract being in the main supplied through pipe 31, and valve 48'there being a larger flow'of extract returned through such pipe 31 and valve 48, than through pipe 4.0, since there'is a con-. siderably larger volume drawn in through the surface of the rotaryfilter in producing a layer thereon than there is drawn through the samein washing such layer, and thepor- 'tion divided out and sent forward to the stationary filter46 isrelatively small. It will be understood that.whenever the level of the mixture in the chamber falls below a predetermined point, the deficiency is made up by diverting a larger portion of the overflow from separator 28, through pipe 31. The mixture of extract and material,

" thus produced in the bottom of the extractor chamber being incontact with the submerged portion of the filter drum-1, a quantity of the fluid extract is drawn from such mixture in the base of thechamber through the submerged sections 4 of ,the drums'cylindrical .surface by .pump -17 acting through pipe .12 and port 8. A layer ofthe material/is thus caused to deposit on the surface of the drum, such layerforming-r continuously .to approximately uniform thickness asthe drum rotates.

it rises above the level of the mixture is, of course,- wet, that is, it includes a" considerable content of the extract; however, the

suction of the pump 17 continues to be exerted upon said layer. after it has thus passed out of the body of mixture in the bottom of the, extractor chamber until the upper limit of the port 8 has been passed by the ports'5 in the commutatrator 26 is disposed to discharge the weaker extract received from said separator on the The material thus deposited on the drums surface-as surface of the drum along a line just safely.

above that which the sections of'said drums surface must-reach in'order to be in communication with said port 9; The additional flow of solvent thus, run onto the material from the feed box is drawn through the ma: terial by. the pump 16 and by it conveyed to the next separator in the series, viz.,sep-

' arator 27. The sections ei of the drums 38 onto the layer of material covering the surface are next brought into communication in succession with port 10 connected with pump 15, the second trough or feed-box being disposed so asto discharge the fresh solvent receivedfrom the reservoir drums surface along a line just beyond that which the sections must reach in order to first come into such communication with such port 10. Finally the sections, one by one in the illustrated construction, come into registerwith the port 11. This port is connected with the air line 32 through Which the air: that is drawn by the several pumps and then separated fromthe solvent in the separators is returned to the extractor chamber. This air blows through the filter membrane that formsthe outer surface of the drum and thus assists in loosening the layer of material thereon so that the latter may be easily removed by means of a 'scraper 50 which delivers the extracted material onto a conveyer 51 that serves'to continually convey the same outside. of .the housing as fast as it is received from the revolving extractor drum. I

It should benoted at this point that the rate of rotation and degree of suction are intended to be such that not only will the extract or solvent be sucked through the layer of material, but air from within the housing will also be drawn through the. layer, thus mechanically displacing in a 35 measure the residual solvent or extract between the particles of material in such layer.

- Both air and extract or solvent, of course,

' are drawni'ntd the several pumps and are then delivered into their corresponding separators. This same air, after separation, is available for loosening the layer of exhausted material, no outside, air being required to be introduced at any stage of the operation. c It will be further noted that after the extract is separated, from the material picked rial remaining on the drums surface is washed one or more times by weaker extract, and finally-by entirely fresh solvent, as the extractor .drum rotates; also that the extract from each extraction, as'such drum'rotates,

' is kept separate from the extract of all the other extractions and the fresh solvent fed into the box or trough 35 is next fed into against the entrance of air or the escape of :a general direction substantially opposite to that in which the current of solvent, freshly received at. the feed box 35, is caused to move as it is brought intermittently into contac tual relation with the material as the latter 6 is picked up-and carried around the drum.

' without the apparatus.

Counting the extractionsas Nos. 1, 2, 3, etc., beglnning with the fresh solvent wash, and the last extraction, viz., that obtained through the submerged portion of the drum, a

it will be noted that we have placed the regu- 'lator 42, so that it will regulate according to the density of extract from the next tothe last extraction. It should be understood,

however, that this regulator can be placed in any portion of the circulation so as to regulate according to the densityof extract at the preceding extraction; preferably, however, we place it as shown near the final extraction,.-at which pointthe extract is nearly full'strengthf Passing nowgfrom the extractor proper, the treatment of the discharged extracted material delivered by the drum 1 to conveyer 51 will next be traced. Such conveyer, comprising a closed tube within whichrevolves a screw of usual form, extends tothe'upper end of a vertically disposed cylindrical chamber 52 that forms a heater where the solvent remaining in the material is removed Within the steamer chamber are arranged a plurality of shelves 53 which open alternately at the center and periphery of the chamber. A central rotatable'shaft 54 extends longitudinally of the chamber and carries rakes 55, or like devices; which' move over .and just above the several shelves, being adapted to turn over the material on said shelves and to gradually move the same in a spirally inward or outward direction,

as the case may be, depending upon whether the shelf opens centrally or at its periphery.

The entering material is thus spread out and broken up on the upper shelf, fed gradually across it, dropped onto the next lower shelfv [and so on'from shelf to she lf'until such materialreaches the bottom of the chamber where it is received by the inner end of another screw conveyer 56 that delivers it The screw in this conveyer, as in conveyeh551, stops short of the opening in,the conveyer pipe so that a portion of the steamed material fills such opening and practically sealsfthe steamer vapor. v

' Atthe same time that the material is-being turned over and raked on the several shelves and gradually fed down through the steamer chamber 52, steamis admitted near the base of the latter by way of pipe 57, such steam risingin a; zigzag path in contact with the constantly changing surfaces of the body-of material that passes downwardly through oughly vaporize the s lvent inixed with such material, so, that substantially all such solvent, escapes finally through a vapor pipe 58 which carries it to a condenser coil 59 in the tank 60. The action of this opposing current of steam 0n the material is to thorvent is driven 01f bythe steam to this con-' denser coil. From the latter the condensed steam and solvent flow by way of a sight box 61 into a condensation main 62, whereby they are conducted to a separator, which will be described later.

In mentioning the excess of. steam accompanylng the solvent vapors, we w1sh to point I out the fact that the solvent vapor will be greatly in excess and thatthe steam is presout only in small amount. The amount of steam present will actually be ependent upon whether the apparatus is being forced or not. If it is being forced, the excess .of

steam-will begreat. If it is being ,worked' at a rate suitable to its capacity,the excess of steam will be quite small.

The supply o'f steam to the steamer cham-' her by way of pipe 57 is cbntrolled by a valve 63, whichis'in turn operated by means of a thermostat 64 mounted at a suitablepoint in the wall of the chamber 52,- so as to be in contact with the Vapor within the latter. Inasmuch as the temperature of such vapor, consisting, as it does, of a mixture of steam and solvent, will vary, upon the relative proportions of the two inedients, gradual change steamer varying different proportions temperature which, if I maintained at the selected point "in the vapor space within the steamer chamber, will insure the practically complete absence of solvent or solvent vapor at the base of the steamer. Accordingly, by properly locating the thermostat and adju'stin'g itsaction, such thermostat may be adapted to automatically control the steam entering pipe 57, so as to'etfect a practically complete recovery of the solvent in the matesigned for the separation of rial without the waste of steam.

The course of the final extract overflow.-

ing'from separator 28 will now'be followed,

such extract first passing, as previously'indicated', into a filter 46, the function of 4 which is to remove any particlesofinsoluble material which may have passed through I so the filter membrane on the drum. From this filter the liquid extract is then led .by way of pipe '65 into the? top of a distillation'column 66which may-be of any. suitable construc- 1 tion, although preferably made cylindrical,

as shown, with its upperportion filld"Wltll broken coke or similar packing, resting upon a grating 67 ,-while its lower portion isfilled condensate from coil 59.

depending it follows that there-will be a; of temperature within the from bottom to top withthe of steam and solvent vapor, and that there will be some certain pipe 85 intothe of the apparatus, '38, the-extractor chamber 18, the chamber with a similar material resting upon a secthermostatically controlled supply valve 63 of the steamer chamber 52. f Such thermostat 71 is conveniently located so as to extend =into the space between the two bodies of filling material Within the column.

The. extract flows down from the filter through the material filling this column and meets therein the upward current of steam which serves to vaporize the solvent,

.but'leaves the oil and any water that may have been included in the extract. Such oil and water together with the added water of condensation of the steam condensed in the distillation leave the column by way-of a plpe 7 2, connected withtwotanks 7 3, while the solvent vapor and any excesssteam pass out by way of pipe 74 and are led toa con denser coil 75 in the tank 60 from which the condensate passes through a sight box 76 into the same'main 62 that receives the The oil that flows from the bottom of the column 66 will be emulsified with thecondensed water, and the function of'the tanks,

73, which receive the mixture, is to permit such oiland water to separate. After separation, the water may be drawn off through outlets 77, and if there be any solvent still present in" the oil, steam can be admitted through a pipe 78 branchingfrom pipe 69,

so as to vaporize such; solvent which is then conducted -'through a vapor pipe 79 toa third coil 80 the'tank 60 from which the, condensate flowsby' way of ,sight box .81

into the condensation main 62- The oil left in the tanks 73, may be, withdrawn, as de sired, by pi e 82;

The con ensation from,.the several coils in theconden'ser, united in the'condensation main 62, is led into the separator 83,-where a gravitational separation of the solvent from the water formed by the condensed.-

steam occurs. The particular form of-separator illustrated, in'keeping with the remainder of the apparatus, is primarily dewater from. a heavy solvent, such'as carbon tetrachlorid.

The water, accordingly, Wlll overflow lit thmgh a P 8 to te-while the (16- wateredsolvent overflows through another v storage tank 38, previously referred to in connection with the'description of the extractor.

'A- gasometer 87 is connected by means of I a branched pipe 88 with the different pieces 41 containing the hydrostatic device and the several separators. 26, 27 and 28 together with the filter 46, so as to maintain a ncluding the storage tank the body of air or vapor within the .ex-.'

will rise or fall accordingly.-

hand is returned to such housing after sepauniformwapor pressure throughout the apparatus and avoid loss ofsolvent vaporu As tractorhousing and above the surface of the solvent in such various'parts of the apparatus changes in volume, owing to change of temperature or other cause, the-gasometer It should be observed all air or vapor, or vapor mixture, which is drawn; by. the

pumps15, 16 and 17thr0ughthe material on the rotating extractor drum' 1, comes from within the housing 18 of said extractor ration from the solvent or extract in the separators 26, 27 and 28, being partially re-. I turned to said housing under pressure through the port 11 and the extracted'material 'on the drum, and otherwise through the elief valve 34which is set to maintain a groper pressure upon'said port 11. In this way no vaporized solvent is lost as no air is discharged from the apparatus and by disrators than those shown may be used for separating'the solvent or'extract from the air or vapor.

placing solvent in the material by air or vapor in this manner a more thorough extraction is obtained at each washing and fewer washings are required to attain a definite degree of total extraction and what is also important, the material leaves the drum much-drier than it would otherwise be if merely drained without air washing; furthermore' there is less solvent carried over into thesteamer' 52 and correspondingly less steam is required to be used there.

, It will. be evident that other ways of applying suction to the drum may be substituted for the pumps shown and an independent air pump may also be used to furnish air for blowing the material at the port 11. It will also be apparent that other forms of sepa- If superheated steam be used in the steamer for evaporating and deodorizing, the rod-uct leaving at 56 may be made near y dry, that is free from w'ater; but if no superheated steam be used and it is desired to further dry the material after steaming it may be delivered by the screw conveyer into any form of drier suitableto the purpose and therein continuously dried as desired. r

Certain other minor modifications, moreover, would require to be made in the details shown, in order to fit the apparatus to work with difi'erent solvents the details shown and described being designed for the use of carbon tetrachlorid as heretofore stated; but anyone skilled in the use of solvents will readily understand the nature of the modifications necessary for the substitution of other solvents, and hence the present description is 'not burdened with. an enumeration of them.

' extractor.

indicating the'latter constituent. tract (mixture of solvent and soluble) thus meaeei I The general operation of the apparatus as a whole and the various steps included 1n our improved process or method of extraction, may be best comprehended by reference to Fig. 2, which is in the nature of a flow chart, and showsthe movements of material, solvent, oil, vapor, water, etc.,

' inthe apparatus of Fig. 1. This flow sheet tion of thearrows. The residuum, still containing all three ingredients, but with the proportion of soluble'much reduced, is discharged from the extractor and thence con- Iveyedtosteamer chamber 52. While such material has lost in soluble during its passage through the extractor, it has now an additional ingredient consisting of the residual solvent which isnot removed in the In the steamer chamber, the material, with the soluble thus extracted to a minimum, is brought into contact with the current; of steam, which passes through the steamer and is condensed at the same time that it evaporates the solvent. The

' latter, together with any excess of steam (which remains uncondensed), passes out into thecondenser 60, while the residual material with its content of water increased by the: condensed steam, but with the ,solvent entirely eliminated, passes downwardly and out.

Reverting to the extractor, the fresh sol; vent from the storage tank 38 passes through the material on the drum l at A, taking up a relatively small amount of soluble, as represented by the narrow band. Such solvent with this small content of soluble is then passeda second time through the stream of material at B, this time taking up from the material more soluble, as

shown by the increased width of the band The ex-- obtained is then delivered into the base of the extractor where it is mixed with incoming materlal and a third time separated therefrom at C, taking up still more solu-- ble, as shown by theincreasedwidth of the band. The resulting extract isdivided into two streams, part being returned into the base of the extractor, while the other part, the finished extract as it may be termed, passed into to the column 66.

thefilter 4:6 and thence 1 I and at the same time is itself condensed.-

In the column the extractis brought into contact with a counter-currentof steam which vaporizes the solvent in the extract,

The solvent'vapor and any'excess of steam willbe seen passing out of the top of the column to the condenser '60, while the oil or other extracted substance, together with a content of water formed by the condensed steam leaves the column at the bottom and passes into the separating tank 73 where the oil is finally obtained'substantially free -.of water.

The solvent vapor and any excess steam after condensation in condenser 60, are combined w1th the'cond'ensation fromthe steamer chamber and pass to the separator 83, I whence the -water is discharged to waste, and the'de-watered solvent passes through the pipe 85', to the storage tank 38.

The modification in construction illustrated in Figs. 3,4 and 5, as has already been indicated, relates entirely to the extractor The apparatus illustrated in the figures just. named, in other words, is intended to be substituted more or less bodily for the extractor inrFig. 1, including the housing or chamber 18 with the rotating drum and other parts inclosed therein. In

the Ipresentcase, however, certain of the pumping and separating elements of the l apparatus .are as a matter of convenience 'inclosed. along with the filter mechanism,

although the exterior connections and the arrangement of the apparatus otherwise remain unchanged. I

' In the extractor. shown in Fig. 1,: the

material to be extracted is first mixed with a quantity of extract and then is given a succession of washings with weaker extract (finishing with fresh solvent) upon the rotary drum 1, such successive washings or extractions following one another relatively. quickly. .We have discovered, however, that in dealing with at least certain materials, the time element is an important factor inattaining completeextraction; in other words, it'is desirablebetween successive washings to permit the material to steep or soak in the extract orsolveht, as the case may be, for a greaterior less time,

and when this is done, fewerwashings willobtain a greater. degree of extraction, or,

with the same number of washings, a more perfect ,degree of extraction may be .obtalned. Not only is' this true, but if .in

' addition the material andsolvent be mixed mechanically while soaking between washings or extractions, the effect is. increased, this being due undoubtedly to the more rapid diffusion of the solvent within the particles of material caused by the stirring, Y

The modified apparatus under consideration accordingly comprises, instead of a single-filter drum, a series of such drums though the number may be greater or less as desired. These .drums are mounted in separate compartments 95, that form sections of a closed tank, the upper portion 96 of which is removable as shown, and may be sealed against escape of vapor by placing water in the lute 97.

The material to be extracted is fed in byway of a spout'98 into a hopper 99 which opens into thebase of the tank compartment 95 in which ismountedthe first drum 91 of the series. The operation of this hopper is identical with that in the previously described construction, .and the level of the mixture within the tank is maintained by means of a regulator 100 similar to the re'gulator 22 in Fig. 1, and hence not shown in of pipes 101(Figs. 4 and 5) so that the same level of liquid is maintained in each.

The drums are rotated all in the same.v

direction, as indicated. by the arrow in spective drums, such shafts being driven by sprocket'chains 106 from the same shaft that rotates the drums. Likewise associiFig. 4, by means ofshaft 102 which extends ated with. each drum'is a scraper 107 which operates as the scraper in Fig. 1 toremove the material from the corresponding-drum and pass it into a screw convey'er 108, the latter extending through the series of compartments alongside of the drums therein. While such conveyor is thus continuous, the trough in which it runsis provided with openings-109, so that the material received in the conveyer from one drum may be dischargedinto the compartment of the next adjacent drum. The final discharge end of the co'nveyer extends without the casing of the inclosing chamber or tank. The shaft 110 of the c'onveyer screw similarly extends without such casing at the .opposite end inorder to be connected with suitable driving means, as need notbe further explained.

In: connection with each of the filter drums, there is provided a pump 111 and a separator 112, which serve the same functions as do the correspondingparts of the first-described apparatus. The pumps are operated from'thc' general drive shaft 102 by means of gears 113. v

' The general ronstrmtion and mode of operation of theindividual filter or extractor 1 9 4:0 utilized, as shown in Fig. 1 While the air is thus returned tothe same drum through the surface of which it was drawn by thedrums in this modified apparatus are the same as in the case of the single drum 1n the first described form of the apparatus, each drum comprising an .outer surface of vfilter membrane divided into sections 1114 that communicate by way of ports 11.5 in.

a commutating valve member 116 with other ports 119-120+121 in a stationary valve member 118. There are, however, (see Fig. 4:), only three ports 119, 120 and121, 1n the stationary member in the construction unv der consideration, the two'- lowermost of.

which are connected by branched pipe 122 o with the intake of the corresponding pump 111, while the remaining port 1.19 is connected with the air discharge line 123 from the separator 112 into which such pump discharges. An escape valve 12 seryes to-relieve excessive pressure in this line 112. v

'Port 121 is adapted to communicate only with sections entirely submerged in the mixture. of material and extract in the tank compartment, while the other port 120 communi'cates with those sections of the drums surface which have just passed above the level of the mixture in. question. The

' branch of pipe .122 connected with'ythis latter port contains a reducing valve 125 so as to out down the air drawn by the pump,

through the portion of the filter not submerged, to a point suitable to the capacity of the pump and the requirements for compressed air to be supplied through pipe 123 and port 119. At the same time it is rendered possible by this device to maintain a 'silitable degree of suction upon'the sub-- merged portion of the drum. It .will be understood that this feature of construction can be advantageously incorporated in the case Where but a single extractor drum is action of the corresponding pump, the separated liquid is led by wayv of pipe 126 to a point in the same compartment adjacent to the inlet for the material to that compartment, such material being received 'in'the caseof the first-compartment from the hopper 99, and in'the case ofeach of the succeeding compartments through the respectiveopenmgs 1.09 in the conveyer trough as.

already explained. The point of discharge of these pipes 126 is-accordingly close to the paddleshafts 105-, so that such incoming maternal and the. liquid may be immediately mixed and thejmixture then pass on into the body of the compartment. Theend of each such pipe furthermore dips into a small compartment or -trap 127 best shown in Fig. 5., one side of which connects with the pipe 7 101 that joins the adjacent compartments,

while its upper portion opens into the tank in which the mixture of extract and mater al is maintained as described.

' meshes.

The fresh solvent is fed by way of a supply pipe 128, which enters the last of the series of compartments near the paddle shaft therein where it is mixed with the nearly extracted material, that-is the material-which, upon passing around the filter v drum in said compartment, is finally dis-- charged from the extractor through the conveyer 108. The flow of the fresh solvent through pipe 128 is controlled by a hydrostaticregulating device 129 interposed in the liquid discharge pipe 126 from the 'separator in the second compartment, such device including afloatv 130 that operates a valve 131 in the same fashion as. the float 4-2 operates the valve45 in the apparatus partment. The fresh solvent thus supplied, after being mixed with the nearly extracted material. as already, described, and being partments near the paddles aft in said comfiltered therefrom by the continuous filtering action of the extractor drum in such last compartment, is returned to the small chamber or trap 127 in said compartment. Only a portion of this solvent, orextr'act as it may properly be called, since it now carries a.

small proportion of'the soluble, is passed on to the next compartment, because the 'volume of extract .sucked through the filter drum in' any compartment 'is'gre'ater than the volume of'solvent fed into thatxcompartment and only asmuch extract passes on to the next compartment as correspondsto the solvent feed.

The last preceding observation will apply to the quantity of extract drawn through each of the succeeding filters, such :quantity being greater than the flow of extract to the respective compartments from the one next adjacent thereto. A certain proportion, of

the weak extract obtained by the-operation in this last compartment, will, however, flow a over into the next where it is mixed with the I material being discharged into said com- 'partment from the conveyer 108 and is then filtered in turn on the drum in said com artment. This operation continues stage y stage, until the first compartment in the I seriesisreached, where the freshmaterial .is receivedinto the system. This material willhence obviously be mixed with the strongest extract, so that such extract as is finally discharged from this compartment, after being filtered through" the drum, is of- .approximately the full desired strength.

ma am The rate at which-this discharge takes place ve'yer108 is of course the same in this as in the previously described apparatus, and need not be touched upon further;

In the case of this modified construction of apparatus, as in the case of the first described form, it has not been deemed essential toshow minor details of construction. Thus the valve mechanism shown in Fig. 4 is diagrammatic-for the sake of clearness just as in the case 0 the valve mechanism associated with the extractor in Fig. 1. In Fig. 5 the valve mechanism is shown as it maybe convenientl although not neces- S2l11ly,' arranged, t eg stationary take-off valve 118 being of rin form slidably mounted on the drum sha t and in slidable contact with the end face o f the drum I through which open the passages that conneet with the. several sections of the cylindrlcal filter surface of the drum. This stationary take-off valve may be held againstrdtation in anyv convenient manner and kept in proper contact with the drum face 'by means of; spring pressure or otherwise as desired. d

' The advantages of the modified construetion and course of procedure involved in the use of the apparatus shown in Figs. 3, 4 and 5 are numerous, but will be only briefly. set forth. In the first place the soluble substance in the material being treated is given amcple time between extractions to diffuse an dissolve in the solvent in the series of pools or puddles that are in efi'ect formed by the successive intermixtures, this action being assisted by the mechanical stirringwhich suchmixtures receive. 'The size of, the filten'drums can be made much-smaller.

than inan apparatus of the type illustrated in Fig. 1 for yielding a given output. Moreover, the several drums aredesirahly-separ rately mounted as shown, and. thus'anyone of them may be 'quiekly removed in case'ot' necessity, and a spare drum quickly piut'in its place, all the drums of course bemgmterchangeable. Accordingly, only ashort shut-f down would be occasioned by .'a1 1 accident-to anyone of the drums, and th1s 1s a very'important consideration in" a continuous 'process like the; one apparatus,

described. In this modified finally,- all the pumps, pipes, separators and other fittings assoc1ated-w1th the extractor are inclo'sed within the casing whereby d -the'pro notion of any extracthigh that inclpses-the filter drums, thus retaining and savmg ny" solvent, whether liquid or r vaporized, that may escape by reason. of-

leal y joints. l

It will'b understood, of course that the number of washin s of the layer oi material on any particular rum in this lastdescribed' apparatus may be increased above that shown as being provided for. :As this would involye an arrangement .in connection" with each of the drums similar in all partlculars to "that illustrated in Fig. 1,'it has not been deemed necessary. to separately illustrate this modification in construction.

In each "of the several forms of ap aratus hereinbefore considered, it will' be 0 served that the material to be treated is caused to pass in a layer of any desired'thickness on a-continuously moving filter surface, whereon it is treated with and separated from the solvent oneor more times, such solvent being caused to pass through the material on the filter in acurrent whose generaldirection of flow isopposite to that of the material. In this manner the untreated material a relatively largefamount of extracted, subis first. treated with solvent containing stance, then 'with solvent containing a" less i amount, and finally withfresh solvent,

thorpu h extraction of the inaterialan 'in extracted matter areobt'ained. I

Thesuccessive, encounters of the solvent with the material being' treated occur in the case of the "individual. rotary extractor or filter while the materiah'is' moving with its component particles substant'al-ly at I rest with respect, to Teach other, ';a

counters or contacts of the solvent with the material is o posite to? the direction of movement of t efilatter; Similarly, in the case of the modified apparatus illustrated in Figs. 3,4; and 5,-where-a "series of.1nte'rmix-ing and separating steps occur, the orv isto be I noted that-tlie. order of ithesuccessive ender of the successive encounters of solvent here with the materialfi's opposite to.

the general direction I,

latter through'theia'pparatiis regarded as an entirety. Forconven enceme may speak of the general directions at How of the currents of solvent and i'nateriajl, which thus "encounter each other; intermittently, as 'be- 1n 're%erence yis'..}'to'=-the order or the successive "encounters of thegsolvent with the maternal in relation .to the latter.

' -.Among the-advantages of the process' may .be enumerated its antomatm and conopposite, it?he'ingv understood that the. I

thedirectionof movement of ti'nuou's character}, Theweight of material and solvent in in fact is relatively very small compare with other extraction processes in which percolatorsifare used to work the material roi'cess, moreover, i'ssm'alli 1 I gag in batches. Accordingly, the capacity of the apparatus is very considerably greater for thesame investment and weight than with the percolator system. It is'possible to reduce the solvent loss to a minimum, as also to employ for such solvent carbon tetrachlorid which has not heretofore been successfully used in commercial practice.

As has been pointed out, among. other things, itis desirable, where this particular solvent is employed, in working feed materials to completely deodorize the extracted material where, as in the case of 'seed meals,

-such extracted material is to be subsequently employed for stock feed or the like. As indicated on-the diagrammatic Fig. 2,

the material to be treated-is regarded as being made up of a soluble and aninsoluble part or component. The action of the'soL' vent on such material is to take up such soluble component of the material being will be'understood, is not a fresh or pure' hich the solvent is finally distilled off, leaving the oil or other extracted substance behind. -The residual or insoluble material reated, forming a solutionfor extract,"fr0m is'that substantially freeof oil, etc., the sol-' ve 'nt absorbed therein being recovered asfullyset forth in thepreceding description.

The fresh solvent is that which is thus recovered-from the extracted material and fromlthe, distillation .step', or from other outside sources, and is admitted to the extractor in regulated quantity, as has like-.

wise been set forth. Except as thusinitially admitted to the extractor, the solvent, it

solvent, but contains extracted substance in solution in an amount depending upon the number of times it has come into contact with the material bein treated, and other considerations. The so vent, once admitted to the system remains in, circulation, being "used over and oyer again. Such solvent it will be further observed, fi'ows'in a substantially. closed circuit, the current being, indeed, divided or branched after leaving the extractor, some containing the dissolved constituents of the materiah' going' in'one direction, an some, ab'sorbed'in the residue, going 1n another direction, 'but such branched currents are united into one current again in passing through the extractien stage, as-shown in Fig. 2. Accordingly the term closed circuit'may be properly applied. tosuch solventflow, and this despite the fact that the solvent may be in the state of a vapor in certain portions of such circuit.

In conclusion it should be explained that the term, solvent, as herein used, is not to be understood as necessarilyto con'note only the fluid solvent employed in our improved process, but it may also refer to such solventwith more or less vof the substance to be extracted carriedin solution therein, ac-

'cording as the context m'ay demand. Similarly the term, air, is meant to connote either atmospheric air, or any other gaseous body; or it may refer to the solvent in vaporlzed state; or to a mixture of such air or other gaseous body with such solvent vapor. .The effect of the closed chamber in which the extraction process. proper takes place, is to restrict this air, whatever its specific character, which may come in contact with the solventby reason of the exposure of the latter in the chamber to such air, to a substantially particular limited y- It is furthermore appropriate in this connection, to refer to the fact that in the case of the steamer chamber in which the material discharged from the extractor proper is treated, as well as in the case of the distillation column. in which the final extract is treated, the thermostatic device may be arranged to control the supply-of material or of extract to theparticular apparatus in question, as the case may be, instead of the supply of steam to such apparatus. In

.other words,the object is to maintain a.

suitable ratio between the rate of supply of steam and material or extract, so as to reg-umaterial, or extract may be recovered therefrom by maintaining a constant temperature of the mixture of solvent vapor and steam at some selected point in the vapor current passing upwardly through such apparatus. Y t V Other modes of applying the principal of ourinvention may be employedinstead of such surface respectively, and separate suction means adapted .to co'iiperate with such filter-surface portions, said liquidsupplying and suction means being connected to pass a current of liquid through such surface portions one to the other.

2. In apparatus of the character delate the degree to which the solvent in such scribed, the combination with a movable fil- I ter having an extended filter surface and means respectively adapted to supply a liquid to spaced portions of such surface,

said filter and means being relatively movable, of separate suction means adapted to cooperate with. such filter-surface portions, said liquid-supplying and suction means being connected to pass a current, of 'liquid in succession through such surface portions.

3. In apparatus of the, character described, the combination of a movable filter having an extended filter surface, relatively stationary means respectively, adapted to supply a liquid to spaced portions .of such surface, and separate'suction means adapted to cooperate with su ch filter-surface' portions, said liquid-supplying and suction means being connected to pass a current of liquid in succession through such surface portions.

4. In apparatus ber, a rotary filter therein having a cylindrical filter surface, relatively stationary means respectively adapted to supply a liquid to circumferentially spaced portions of such surface, and separate suction means adapted to cooperate with such.- filtersurface portions, said suction ,means having closed: circuit connections with said I I chamber.

5.- In apparatus of the character described, the combination of a closed (Ell-fink bar, a rotary filter therein having a cylin-.

drical filter surface, relatively stationary means respectively adapted to" supply :1'

liquid to circumfe'rentially spaced ortions of such surface, and separate-suction means adapted" to cooperate with such filtersurfa'ce portions, said'liquid -supplyinig and suction means being connected to pass a current of liquid 1n succession through such surface portions and having closed circuit con nect1ons with said chamber.

6. In apparatus of the character described, the'combinatio'n of a closed chamber; meansjrespectively adapted tosupply to said chamber materialbeing treated and a suitable solvent, so as to maintain a mix ture thereof in said chamber; a movable suction .filter in said chamber adapted to,

contact with such. mixture; and means adapted to remove material from said filter and discharge the same from said chamber.

7. In apparatus of the character de scribed,'the' combination of a closed chainv a suitable solvent, so as to maintain a mixbe'r; means respectively adapted to supply to said chamber material being treated and a suitable solvent,'so as-to maintain amixtu-re thereof 1n sald chamber; a rotary suction filter in said chamber'having a portion of its surface disposed to contact with such mixture; and mea ns adapted to remove ma-I' terial from said filter" and discharge vthe same from said chamber.

'8. Ihqapparatus of the. character scribed, the combination ofa closed chamber; means-respectively adapted to supply to said chamber material being treated and ture thereof in said. chamber, a rotary cylindrical suction filter in said chamber having Y a portion'of its surface disposed to Contact with such mixture; andjmeansadapted to of the character de-. scribed, the combination of a closed sham- 9..' InIapparatus of the character ide scribed, th'ei' combination of a closed chamber; independent means'ad'apted to supply to saidchamber the material being treated and a suitable, solvent respectively; means within I said chamber adapted to fmix r suchmaterial andsolvent; a movable suction filter in said chamber adapted to contact with such mixture; and means adapted to remove "remove niateria'l from said filter and charge. the same from said chamber.

material from said filter and'discharge the same from. saidcham'ber. I 10. In apparatus of the character described, the combination ofa closed chamterial being treated and a. suitable solvent;

I ber adapted to contain a mixture pf the ma- I means adapted to supply? such material to" said chamber below the level of the mixture U in the latter;'independent me'ansjadapted to supply such solvent to said chamber; a-

movable@ suction filter in said chamber 1' adapted to-f contact with such mixture; and

means-adapted to remove material from said filter and discharge the same from said chamber.

'11. In apparatus of the 'character"- described, the combination of a suction jfilter';

means adapted to return the airnsucked therethroug'h to the high pressure sideof said filter, substantially as described; and 1 means adapted to confine such air to a substantially particular limited body.

substantially particular limited body. I I 13. In apparatus of 'the character 'de scribed, the combination. ofa rotary cylindrical filter; means confinin the air that comes .in contact with said lter, to a su'b stantially particular limited body; and suction meansadapted to pass such air over and over, again through said filter..

. 14; Infapparatils of the 'charactendescribed, the combination of a filter hav ng an extended filter surface; meansadapted 'to supply a liquid todi'iferent portions'of such surface respectively; separate suction" means adapted to cooperate with such filtersurface portions;'means adapted to return the air sucked through sa d filter to the high pressure side of thesanie; and means.

adapted' t o ,confine such air to'asubstantially articularlimited body,

to supply aliquid to diflere'nt portions of such surface respectively; separate suctlon means adapted to cotiperate with such filtersurface: portions, said liquld-supplyin'g and I n apparatus ,of the character dc v scribed, the combination of a filter having "an extended filter 'surface'; -means adaptedsuction means being connected to pass a current of liquid in succession through such surface portions; means adapted to return the air sucked through said filter to the high pressure side of. the same; and means adapted to confine s'uch air to a substantially particular limited body.

16. In apparatus of the character described, the combination of a movable filter having an extendedfilter surface; relatively stationary means respectively adapted to supply a liquid to spaced portions of such surface; separate suction means adapted to cooperate with-such filter-surface portions; means adapted to return the air sucked through said filter to the high pressure side of the same; and means adapted to confine such air to a substantially particular limited body.

17. In apparatus of the character de scribed, the combination of a movable filter having an extended filter-surface; relatively stationary ,means respectively adapted to supply a liquid to spaced portions ofsuch surface; separate suction means adapted to coiiperate'with such filter-surface portions, said liquid-supplying and suction means being connected to pass a current of liquid in succession through such surface portions; means adapted to return the air sucked through said filter to the high pressure side of the same; and means adapted to confine such air to a substantially particular limited body.

18.. In apparatus of .the, character de-' scribed, the combination of a closed chamber; a rotary filter therein having a cylindrical filter surface; relatively stationary" means adapted to supply a liquid to cir-' cumferentially spaced portions of such surface; separate suction means adapted to'cooperate with such filter-surface portions,

said suction means discharging without said chamber; and means adapted to separate and return to said chamber the air thereby sucked through said filter.

19. In. apparatus of the character described, the combination of a closed cham- 60 ber; arotary filter therein having acy1indrical filter surface; relatively stationary means adapted to supply aliquid to circumferentially spaced portions of such surface;

I I separate suction means adaptedtocoiiperate with such filter-surface portions,,said suetion means discharging without said-chamber and being connected with said liquid-. supplying means to pass a current of liquid in succession through such surface portions;

and means adapted to separate and-return to said chamber the air thereby suckedf through said filter.

20. In apparatus of the character described, a

the combination of a series of devices adapted to continuously, mix the material to be treated with solvent; a correspondingseries of devices adapted to continuously separate such solvent from the mixtures produced by said mixing devices, respectively; means adapted to supply fresh material to the mixing device at ,one end of the series;

means adapted to supply fresh solvent to the mixing device at the other end of such series; and means adaptedto transfer the separated material and solvent from the intermediate separating devices to the'mixing devices on opposite sides thereof, respectively, in the series, the solvent from the separating device associated 'with the mixing device receiving the-fresh material, and

the material from the separating device associated with the mixing device receiving the fresh solvent, being discharged from transfer the separated material and solvent from the intermediate filters to the mixing devices on opposite sides thereof, respectively, in the series, the solvent? from the filter associated with the mixing device receiving the fresh material, and the material from the filter associated with the mixing device receiving the fresh solvent, being dischargedfrom the'apparatus.

22. In apparatus of the character described, the combination of a series of devices adapted to continuously mix the material to be treated with solvent; acorrespondingseries of suction filters adapted to continuously separate such solvent from the respectively, means adapted to supply-fresh material to the mixing device at one end of the series; means adapted to supply fresh solvent to the mixing dev'ce at the other end of such series; means a apted to transfer 119 mixtures producediby saidrmixing devices,

the'separated material and solvent from the intermediate filters to' the mixing devices on opposite sides thereof, respectively; in the .series, the solvent from the filter associated With'the mixing device receiving the fresh material, and the material fro'm the filter associated with the mixingdevice receiving the fresh. solvent, being discharged from .the

apparatus; and means adapted to return the pressure side thereof.

23. In apparatus of the character described, thecombination of a series of de-. vices adapted to continuously mix the mateair sucked through said filters to the high a I rigfl to he treated with solvent 1 correspond mg series of-suctlon filters adapted 13000111 tinuously.separate siieh solvent fi-mh. the

mixtures-produced. by said mixing device s, l'cspeg-ti'vely,meansndapted to sn'pply fresh 'matcriallto'the njlixing gleviceat one end of the series; means adapted to supply .fresh solvent ,to the mixing device at-the otherend 'ofseich series; means adapted to transfer the separatedmaterial and solvent fromthe I intermediate filters to the. mixing 'devices. )n

opposite sides thereof, respectively, in the series, the solvent from the filter associated With the mixing device receiving the fresh imatefialkhhdliflm aterial from the filter 13* associated withthe mixing. devi'cereceiving the freshlsel vent} being,dischargedfromthe apparatus; a "chamber nclosing the aforesaid "devices amt-filters; and means adapted to retl u'pito; said cl'mmbe'r the bail-" "sucked; 20 through.-"sa'idqfiltelfs,

Signed-byes, this 19th day of December,- 

